Artificial hand



Jan. 12 1926.

I 56 Wm H o E. LAHERTY- ARTIFICIAL HAND Filed Dec. 5; 1923 3 Sheets-Sheet 1 Q Jan. 12 1926.

E. LAHERTY ARTIFICIAL- HAND Filed Dec. 5, 1923 3 Sheets-Sheet 2 V l l Jan. 12 1926. 1,569,286

E. LAHERTY ARTIFICIAL 1mm Filed Dec. 3. 1923 s Sheets-Sheet s Snow M01 E lake/ 7? n r'frreo-oew 1 p 7 )ZM l Patented Jan. 12, 1926.

UNITED STATES PAT NT o1= 1=iic151:.

EDWARD LAHERTY, OF NENANIA, TERRITORY QF ALASKA.

ARTIFICIAL HAND.

Application filed December 3,1923. Serial No. 678,237.

* movement of the forearm stump is used to actuate the thumb and the rest of the gels, the primary object of the invention residing in the provision of suchan artificialhand wherein said fingers and thumb may be moved to open and closed positions without the -occasion of such movements being noticeable to others. The great disadvantage of the present types of artificial hands is that itis generally necessary to move theshoulder or entire arm that carrice the artificial hand, and in some instances, the other arm, hand and fingers, for moving the fingers of the artificial hand to open and closed positions. This is the cause, of great annoyance and embarrassment to the wearer.

A user of the present artificial hand may positively move the fingers and thumb there of to closed and open position by a relatively slight turning movement of the hum-an wrist, and this no matter what the position of the hand may be relative to the body.

It is an additional object to provide a device of this character wherein the foregoing objects may be attained without the 'pro vision of any complex and expensive-construction, the present artificial hand being especially characterized by its extreme simplicity of construction, high efficiency of operation, and inexpensiveness of manufacture, the invention comprising but few parts and these so correlated as to reduce the possibility of disarrangement to a minimum. -A further object of the invention 1s-toprovide a device of this character wherein the necessity of using any shoulder, body or upper arm strap or harness is entirely dispensed with.

lVith the above and other objects in view as the nature of the invention is better understood, the same com-prisesthe novel'form, combination and arrangement of par-tshereinafter morefully described, shown in the accompanying drawings and claimed;

In the drawings whereinthere is disclosed the two most practical embodiments of the present iznventi on'with which I am familiar zit-the present time, and wherein like reference characters indicate corresponding parts :througl-iout Figures 1 to 8, inclusive, and Figures 9, 10, 11 and 12, respectively,

Figure l-is a front-side elevational view I of a prosthetic hand constructed in accordance withthe present invention,

i Figure 2 is an enlargeddiagrammat-ic plan view disclosing the major portion of the finger operating mechanism of the hand, the. hand being shown in dotted lines,

, Figure-3'1'sa detail transverse cross section taken substantially upon the curved line of Figure 2.

Figure 4 is a. longitudinal sectional View taken through one of the fingers and a portion of the palm of the'hand for more clearly disclosing the arrangement of the finger operating cords disposedtherein,

Figure 5 is a detail transverse sectional View through the adjustable fore arm strap element of'the present invention,

Figure 6 is an enlarged elevational view of a slightly tapered metallic sleeve member that comprises an essential part of the present invention,

Figure 7 is an enlarged front elevational view of a metallic band or'ring that is 130- sitioned' upon'the before mentioned: metallic sleeve, the same being held stationarywith V respect to the sleeve'for purposes presently tobe set forth,

Figure 8 is anelevational view of a unit included in thepresent invention, the same having as oneof its elements; the before me tioned metallicv band or ring, said unit adapted to berigidly secured to the fore arm of the wearer andfthis at a point directly adjacent the elbow thereof,

Figure9 'is an enlarged side elevational view partly'in crosssection, of one of the spring members in. the line of connection between the fingers-of the hand and the means for actuating said. connection for providing a slight tension upon the connection whereby the fingers 'of-the-hand are nor mally maintained in their naturalr positions,

Figure 10 is a fragmentary front side elevational view of a slightly modified form of tapered metallic sleeve member employed in conjunction with the modification, said sleeve member adapted for tight lit upon the end of the human stump whereby a rotation of the wrist portion of the stump will manifestly rotate said metallic sleeve element for prvposes presently to be set forth.

First having reference to Figures 1 to 9, inclusive, wherein there is shown the most preferred embodiment of the present invention the same consists of a metacarpus or body part which is hollow and of conventional shape and with which metacarpus or body 5 is formed the. fingers 6, 7, 8 and 9, and the thumb 10. The fingers and thumb are also hollow and comprise the usual jointed sections of conventional form.

The present artificial hand also comprises a wrist portion 11 and a fore-arm portion 12 which fore-arm portion is preferably of suitable leather and secured in any well known manner to said wrist portion 11. This leather fore-arm portion 12 is split longitudinally at one end whereby the same may be tightly engaged with the fore-arm through the medium of suitable lacing 13.

The interior of the wrist portion 11 of the inetacarpus or body 5 is shaped to fit the curvature of the wrist of a particular wearer and positioned over the external surface of said wrist portion 11 is a slightly tapered metallic sleeve 14: that is formed intermediate its ends with a circumferential relatively wide groove or channel 15 and within which is freely rotatably disposed a metallic band or ring 16, Figure 7.

Adjacent the front end of the metallic sleeve let the same is formed with an open housing 17 within which is disposed upon vertically arranged pins a pair of spaced relatively small pulleys 1818. The stationary metallic ring or band 16 is also formed at a point normally out of alinement with the open housing 17 with a similar open housing 19 that also carries a pair of horizontally disposed spaced pulleys 20-20. Secured within recesses 2121 upon opposite sides of said metallic band of ring 16 are the front ends of rearwardly directed relatively narrow and thin strips ofmetal particularly aluminum 2222, the arrangement of these strips of metal being such as not to contact or rub against the fore-arm portion 12 of the artificial hand.

The rear ends of said metallic strips 22-22 are rigidly connected in any manner desirable to a fore-arm strap 23 which forearm strap is to be tightly secured through the medium of lacing 13 or other means to the fore-arm of the wearer, and this at a point directly adjacent the elbow of the arm.

Arranged upon the top side of the interior of the metacarpus or body 5 of the hand is a plurality of horizontally disposed rela tively small cord or cable pulleys 2i which as clearly shown in Figure 3 are five in number, the same being so positioned within the nietacarpus or body 5 of the hand as to register with the fingers and thumb thereof. Similarly arranged upon the bottom or palm of said metacarpus or body 5 is a plurality of other horizontally arranged relatively small cable or cord pulleys 25 which are also five in number and which also aline with the lingers and thumb 6 to 10, inclusive.

Anchored as at 26 within the outermost linger and thumb sections and this upon the palm side of the hand thereof are cables or cords 27 that extend rearwardly, that are guided over the pulleys 25 and that are secured jointly as at 28 to a single cable or cord 29 that passes outwardly through the wrist portion of the hand through an opening 30, and that is passed over one side of one of the pulleys 18-18, carried by the tapered metallic sleeve 14, said cord or cable being then extended slightly downwardly and engaged over the opposite side of the adjacent one of the pulleys 202O carried by the stationary metallic band or ring 16 that is disposed upon said sleeve 14-. This cable is then extended upwardly in an opposite direction and is anchored as at 31 adjacent the rearniost end of the sleeve 14.

Surrounding a normally slack portion 27 of each of the cords or cables 27 is a retractile coiled spring 32 the opposite ends thereof being secured as at 33 to different points of the respective cable 27. These coiled springs 32 serve to normally apply a tension to each of the cables or cords 27 for maintaining the fingers and thumbs in positions of reality.

Anchored to the back sides of the lingers or thumbs and at a point within the fingers and thumb at Set, Figure 1-, is another series of cables or cords 35 that extend rearwardly and are guided over the pulleys 21 at the back side of the interior of the hand and are jointly connected as at 35 to a cable or cord 36 which extends or'ltwardly through the Wrist portion 11 of the hand through an opening 37. This cable or cord 37 is then passed alongside of the ren'iaining one of the pair of pulleys l818 and then upon the inner side of the remaining one of the pair of pulleys 20-20 carried by the stationary band or ring 16. This cable is then anchored as at 38 to the rear end of said metallic sleeve 1 1.

When the hand is applied to the stump of the arm the position of the different parts are as shown in Figure 1, and it will be at once obvious that when the wrist of the arm stump is given a slight turn in opposite directions, said metallic sleeve 1% will be rotated for obviously pulling upon the cables 29 or 36 as the case may be for opening or closing the fingers with respect to the metacable for thereby allowing this action.

In the modified formof the invention shown in FigureslO to 12, inclusive, the hand comprises a metacarpus or body 5 of a constructionsimilar to the metacarpus or body 5 of'the hand shown inthe preferred embodiment=of the invention. This metacarpus or body 5 is also formed with a relatively short wrist portion 11 and in this form ofthe inventionthe body 5 is provided with fingers and a thumb of a typeshownin the patent to Charles Hofer, No. 1,305,721, or to Alexander Pringle, No. 1,324,564. The fingers disclosed in the before mentioned patents are of the coiled spring-type, and extending through each of which is a cord or cable that is attached to a master cable-whereby a pull upon the same will move the fingers and thumb to a closed position, the normal arrangement of the fingersand thumb being in a partially closed or natural state. 'However, the construction above set'forth does not enter into the spirit and scope of the present invention as the same is conventional and will therefore not be claimed by me eitherseparately or in combination with the other elements of the invention.

In this form of the invention, the wrist portion 11 of the metacarpus or body 5 is secured within a tapered metallicsleeve 14 that is reduced in circumferential area at its opposite ends and upon which reduced portions are disposed metallic bands or rings 16' and 16; The interior of the metallic sleeve 14 is provided with a felt padding 40 shaped to the curvature of the wrist of the wearer, whereby slight relative turns of the wrist in opposite directions will manifestly occasion slight turning movement of the sleeve 14 as well as the metacarpus or body 5 and fingers and thumb of the hand.

Rigidly connected to the rings or bands 16 and 16 are rearwardly extending strips of metal 2222, similar to the metal strips 22-22 in the before described embodiment of the invention. Carried by the rear ends of these metal strips 22 2 is a leather strap 23 that may be secured to the forearm of the wearer in any manner desirable it being herein noted that this strap 23 is also secured to the fore-arm at a point directly forwardly of the elbow of the arm.

The master cable from the fingers above set forth is designated by the reference character 41 and in this instance the same also extends outwardly of the metacarpus or,

body 5 of the hand through an opening 42 in the -wrist portion thereof, saidmaster cable being engaged over a horizontally arrangedpulley 42: upon the foremost one of the bands or rings, which foremost one. is designated by the reference character '16. The master cable is then extended rearwardlyand-engages over the-opposed side of a pulley 43 that is carried by the sleeve 14 and this at'a point slightly out of alinement withsaid'first mentioned pulley 42; The master cable 41 is finally anchored as at 44 to the rearmost ring or band 16".

It will thus be obvious that in actual use the stump of the arm designated A will'be associated with the present artificialhand in a manner somewhat diagrammatically shown in Figure 10. A slight turning movement of the wrist of the stump will manifestly slightly rotate the sleeve 14 together with the wrist, body portion and fingers and thumb of the hand, for thereby closing orallowing the fingers and thumb to .open as the case may be. A turning movement of the wrist in a direction as indicated by the arrow in Figure 10 will obviously cause. the pulley 43 to draw the master cable-41 outwardly through the interior of the hand, which will obviously pull upon the cables carried by the fingers and thumb ofthe hand which will manifestly move the fingers and thumb to a closed position.

From the foregoing it will be readily apparent to those skilled in the art to which the present invention pertains, that'I-have provided a highly novel, simplified and inexpensive form of artificialhand, and one that Will effectively anticipateall of the objects above ascribed.

Idonot wish to be limited to the specific construction and arrangement of the parts disclosed in the forms of the invention set forth, as in the future practice of the invention other changes and modifications may be had Without departing from the spirit and scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. In an artificial hand, comprising a body terminatingin a wrist portion and having a thumb and fingers articulated thereon, means for securing the wrist portion to the end portion only of the forearm of the wearer, and means carried by the wrist portion of the hand body relatively rotatable thereon adapted to be connected to the forearm only of the wearer rearwardly of the connection of the hand body, a rotative movement of the wrist portion of the hand body effecting a movement relative to said means for operating connections with the and having thumband fingers articulated thereon, means for securing the wrist portion of the body to the end portion only of the forearm of the wearer, cable connections with the thumb and fingers of the hands directly connected to the Wrist portion of the hand body, and means carried by and relatively rotatable on the wrist portion of the hand body secured to the forearm of the wearer, rearwardly of the connection of the hand and body thereto, for operating said cable connection in a relative rotatable movement ot the forearm for positively operating the lingers and thumb to open or close the same.

3. In an artificial hiand, comprising a hand body terminating in a wrist portion and having a thumb and fingers articulated thereon, means for securing the wrist portion to the end of the forearm of a wearer, cable connections with the thumb and fingers of the hand directly connected to the wrist portion of the hand body, a member mounted on the wrist portion of said hand body and rotatable relative thereto having means for connecting said member with the forearm only of the wearer rearwardly of the end portion, said member engaging said cable connections and operable upon a relative turning movement of the end or the forearm of the wearer in opposite directions tor effecting a positive operation of the lingers and thumb on the hand body, tor opening or closing the same.

at. An artificial hand comprisinga hollow hand body, hollow fingers, and a hollow thumb, mounted on said body for articulation relative thereto, and operating means for said fingers and thumb including cable connections with the back portions of the fingers and thumb, and movable through the back portion of the hand body, cable connections with the palm portions of the fingers and thumbs and movable through the palm portion of the hand body, each of said cable connections being anchored to the wrist portion of said hand body adapted to be secured to the wrist of the forarm of a wearer, and operating means carried by the wrist portion and engaging said cable connections operable upon a relative rotative movement of the wrist of the hand portion and the forearm of the wearer for ettecting a relative movement of said cables to produce a positive movement of the fingers and thumb in opening or closing the same.

5. An artificial hand comprising a hand body, thumb and fingers articulated thereon, means tor securing the hand body to the stump of the forearm only or the wearer, means mounted only on the forearm having a portion relatively movable on the hand body, and means carried by the hand body operable upon a relative movement of the hand body and the portion of the last men tioned means thereon for positively operating the lingers and thumb to open and closed position.

6. An artificial hand, comprising a hand body, thumb and fingers articulated thereon, means "tor securing the hand body to the stump of the forearm only of the wearer, means mounted only on the forearm of the first mentioned means having a projecting portion relatively movable on the hand body,

and cables connected to the thumb and fingers of the hand body operable by the projecting portion of the last mentioned means for producing a positive operation of the thumb and fingers to open and closed posi...

tion.

In testimony whereof I aflix my signature.

EDlVARD LAHERTY. 

